AMPK inhibition sensitizes acute leukemia cells to BH3 mimetic-induced cell death.

BH3 mimetics, including the BCL2/BCLXL/BCLw inhibitor navitoclax and MCL1 inhibitors S64315 and tapotoclax, have undergone clinical testing for a variety of neoplasms. Because of toxicities, including thrombocytopenia after BCLXL inhibition as well as hematopoietic, hepatic and possible cardiac toxicities after MCL1 inhibition, there is substantial interest in finding agents that can safely sensitize neoplastic cells to these BH3 mimetics. Building on the observation that BH3 mimetic monotherapy induces AMP kinase (AMPK) activation in multiple acute leukemia cell lines, we report that the AMPK inhibitors (AMPKis) dorsomorphin and BAY-3827 sensitize these cells to navitoclax or MCL1 inhibitors. Cell fractionation and phosphoproteomic analyses suggest that sensitization by dorsomorphin involves dephosphorylation of the proapoptotic BCL2 family member BAD at Ser75 and Ser99, leading BAD to translocate to mitochondria and inhibit BCLXL. Consistent with these results, BAD knockout or mutation to BAD S75E/S99E abolishes the sensitizing effects of dorsomorphin. Conversely, dorsomorphin synergizes with navitoclax or the MCL1 inhibitor S63845 to induce cell death in primary acute leukemia samples ex vivo and increases the antitumor effects of navitoclax or S63845 in several xenograft models in vivo with little or no increase in toxicity in normal tissues. These results suggest that AMPK inhibition can sensitize acute leukemia to multiple BH3 mimetics, potentially allowing administration of lower doses while inducing similar antineoplastic effects.

Impact of inotuzumab ozogamicin on outcome in relapsed or refractory acute B-cell lymphoblastic leukemia patients prior to allogeneic hematopoietic stem cell transplantation and risk of sinusoidal obstruction syndrome/venous occlusive disease.

We evaluated 58 patients with relapsed or refractory (r/r) acute B-lymphoblastic leukemia (B-ALL; median age, 42.5 years; range, 16-69 years), treated with inotuzumab ozogamicin (INO) between 2016-2022 and who received an allogeneic hematopoietic stem cell transplantation (allo-HCT) consecutively. Forty-seven (81%) of the 58 patients were heavily pretreated receiving intensive chemotherapy +/- TKI, blinatumomab in 24 (41%) and allo-HCT at first-line in 11 (19%) patients. Complete remission (CR) rate prior to allo-HCT was 84%. Median follow-up was 30.5 months and median overall survival (OS) measured from start of INO was 11.2 months. Oneand 2-years OS rates were 50% (95%-CI, 38.4-56.1%) and 36.7% (95%-CI, 25.5-52.9%), respectively. Sinusoidal obstruction syndrome/venous occlusive disease (SOS/VOD) after allo-HCT occurred in 17 (29%) patients. Of those, 9 (53%) patients died due to SOS/VOD and multi-organ failure. Two had received >2 INO cycles (3 cycles, 5 cycles, n=1, each), all others ≤2 INO cycles prior to allo-HCT. Logistic regression analysis revealed conditioning with double alkylators (P=0.038) and allo-HCT during first-line therapy (P=0.050) as significant risk factors for SOS/VOD and in trend allo-HCT ≤ 60 days from last INO application (P=0.07), whereas number of INO cycles before allo-HCT and time between last INO application and allo-HCT were not significant. Relapse/progressive disease occurred in 20 (34%) patients. Of those, five (25%) patients are still alive, whereas 15 succumbed of their disease. Treatment with INO seems to be an effective approach with successful bridge-to-transplant. However, risk of SOS/VOD is high, necessitating continuous monitoring and recognition of SOS/VOD risk factors.

A phase 2 and pharmacological study of sapanisertib in patients with relapsed and/or refractory acute lymphoblastic leukemia.

BACKGROUND: Despite recent approval of several new agents, relapsed acute lymphoblastic leukemia (ALL) remains challenging to treat. Sapanisertib (MLN0128/TAK-228) is an oral TORC1/2 inhibitor that exhibited preclinical activity against ALL. METHODS: We conducted a single-arm multi-center Phase II study of sapanisertib monotherapy (3 mg orally daily of the milled formulation for 21 days every 28 days) in patients with ALL through the Experimental Therapeutics Clinical Trials Network (NCI-9775). RESULTS: Sixteen patients, 15 of whom were previously treated (median 3 prior lines of therapy), were enrolled. Major grade 3-4 non-hematologic toxicities included mucositis (3 patients) and hyperglycemia (2 patients) as well as hepatic failure, seizures, confusion, pneumonitis, and anorexia (1 patient each). Grade >2 hematological toxicity included leukopenia (3), lymphopenia (2), thrombocytopenia, and neutropenia (1). The best response was stable disease in 2 patients (12.5%), while only 3 patients (19%) were able to proceed to Cycle 2. Pharmacokinetic analysis demonstrated drug exposures similar to those observed in solid tumor patients. Immunoblotting in serially collected samples indicated limited impact of treatment on phosphorylation of mTOR pathway substrates such as 4EBP1, S6, and AKT. CONCLUSION: In summary, single-agent sapanisertib had a good safety profile but limited target inhibition or efficacy in ALL as a single agent. This trial was registered at ClinicalTrials.gov as NCT02484430.

DNA methyltransferase inhibitor exposure-response: Challenges and opportunities.

Although DNA methyltransferase inhibitors (DNMTis), such as azacitidine and decitabine, are used extensively in the treatment of myelodysplastic syndromes and acute myeloid leukemia, there remain unanswered questions about DNMTi's mechanism of action and predictors of clinical response. Because patients often remain on single-agent DNMTis or DNMTi-containing regimens for several months before knowing whether clinical benefit can be achieved, the development and clinical validation of response-predictive biomarkers represents an important unmet need in oncology. In this review, we will summarize the clinical studies that led to the approval of azacitidine and decitabine, as well as the real-world experience with these drugs. We will then focus on biomarker development for DNMTis-specifically, efforts at determining exposure-response relationships and challenges that remain impacting the broader clinical translation of these methods. We will highlight recent progress in liquid-chromatography tandem mass spectrometry technology that has allowed for the simultaneous measurement of decitabine genomic incorporation and global DNA methylation, which has significant potential as a mechanism-of-action based biomarker in patients on DNMTis. Last, we will cover important research questions that need to be addressed in order to optimize this potential biomarker for clinical use.

Detection of an atypical BCR::ABL1 fusion in a patient with secondary B-cell acute lymphoblastic leukemia/lymphoma following multiple myeloma treatment.

Secondary hematologic malignancies, such as B-cell acute lymphoblastic leukemia/lymphoma (B-ALL), have been reported following multiple myeloma. Tyrosine kinase inhibitors have improved clinical outcomes of patients with Philadelphia-positive (Ph+) B-ALL. Therefore, recognition of the Ph chromosome in B-ALL patients is important for both prognosis and therapies. We present a case of a secondary Ph+ B-ALL following multiple myeloma that highlights a BCR::ABL1 fusion by a gene fusion assay to reveal a cryptic Ph chromosome, which may otherwise be missed by conventional cytogenetics and typical interphase fluorescence in situ hybridization.

Venetoclax in combination with hypomethylating agent for the treatment of advanced myeloproliferative neoplasms and acute myeloid leukemia with extramedullary disease.

The combination of venetoclax and hypomethylating agent (HMA/venetoclax) has emerged as a treatment option for patients with de novo acute myeloid leukemia (AML) who are unfit to receive intensive chemotherapy. In this single-center retrospective study, we evaluated clinical outcomes following treatment with HMA/venetoclax in 35 patients with advanced myeloproliferative neoplasms, myelodysplastic syndrome/myeloproliferative neoplasm overlap syndromes or AML with extramedullary disease. The composite complete remission (CR) rate (including confirmed/presumed complete cytogenetic response, acute leukemia response-complete, CR and CR with incomplete hematologic recovery) was 42.9% with median overall survival (OS) of 9.7 months. Complex karyotype was associated with inferior median OS (3.7 versus 12.2 months; p = 0.0002) and composite CR rate (22% versus 50.0%; p = 0.2444). Although SRSF2 mutations were associated with higher composite CR rate (80.0% versus 28.0%; p = 0.0082), this was not associated with longer median OS (10.9 versus 8.0 months; p = 0.2269). Future studies should include these patient subgroups.

Allogeneic Blood or Marrow Transplantation with High-Dose Post-Transplantation Cyclophosphamide for Acute Lymphoblastic Leukemia in Patients Age ≥55 Years.

Patients age ≥55 years with acute lymphoblastic leukemia (ALL) fare poorly with conventional chemotherapy, with a 5-year overall survival (OS) of ∼20%. Tyrosine kinase inhibitors and novel B cell-targeted therapies can improve outcomes, but rates of relapse and death in remission remain high. Allogeneic blood or marrow transplantation (alloBMT) provides an alternative consolidation strategy, and post-transplantation cyclophosphamide (PTCy) facilitates HLA-mismatched transplantations with low rates of nonrelapse mortality (NRM) and graft-versus-host disease (GVHD). The transplantation database at Johns Hopkins was queried for patients age ≥55 years who underwent alloBMT for ALL using PTCy. The database included 77 such patients. Most received reduced-intensity conditioning (RIC) (88.3%), were in first complete remission (CR1) (85.7%), and had B-lineage disease (90.9%). For the entire cohort, 5-year relapse-free survival (RFS) and overall survival (OS) were 46% (95% confidence interval [CI], 34% to 57%) and 49% (95% CI, 37% to 60%), respectively. Grade III-IV acute GVHD occurred in only 3% of patients, and chronic GVHD occurred in 13%. In multivariable analysis, myeloablative conditioning led to worse RFS (hazard ratio [HR], 4.65; P = .001), whereas transplantation in CR1 (HR, .30; P = .004) and transplantation for Philadelphia chromosome-positive (Ph+) ALL versus T-ALL (HR, .29; P = .03) were associated with improved RFS. Of the 54 patients who underwent RIC alloBMT in CR1 for B-ALL, the 5-year RFS and OS were 62% (95% CI, 47% to 74%) and 65% (95% CI, 51% to 77%), respectively, with a 5-year relapse incidence of 16% (95% CI, 7% to 27%) and an NRM of 24% (95% CI, 13% to 36%). RIC alloBMT with PTCy in CR1 represents a promising consolidation strategy for B-ALL patients age ≥55 years.

Hyperphosphatemic Tumoral Calcinosis With Pemigatinib Use.

Background/Objective: Pemigatinib, a fibroblast growth factor receptor (FGFR) 1-3 inhibitor, is a novel therapeutic approach for treating cholangiocarcinoma when an FGFR fusion or gene rearrangement is identified. Although the most reported side effect of pemigatinib is hyperphosphatemia, tumoral calcinosis with soft tissue calcifications is not widely recognized as a complication. We report a case of patient with hyperphosphatemic tumoral calcinosis on pemigatinib. Case Report: A 59-year-old woman with progressive metastatic cholangiocarcinoma, despite receiving treatment with cisplatin and gemcitabine for 7 months, was found to have an FGFR2-BICC1 fusion in the tumor on next-generation sequencing. Pemigatinib was, therefore, initiated. Four months into the therapy, multiple subcutaneous nodules developed over the lower portion of her back, hips, and legs. Punch biopsies revealed deep dermal and subcutaneous calcifications. Investigations revealed elevated serum phosphorus (7.5 mg/dL), normal serum calcium (8.7 mg/dL), and elevated intact fibroblast growth factor-23 (FGF23, 1216 pg/mL; normal value <59 pg/mL) levels. Serum phosphorus levels improved with a low-phosphorus diet and sevelamer. Calcifications regressed with pemigatinib discontinuation. Discussion: Inhibition or deficiency of FGF-23 results in hyperphosphatemia and can lead to ectopic calcification. Pemigatinib, a potent inhibitor of FGFR-1-3, blocks the effect of FGF-23 leading to hyperphosphatemia and tumoral calcinosis as observed in our case. Treatment is aimed primarily at lowering serum phosphate levels through dietary restriction or phosphate binders; however, the regression of tumoral calcinosis can occur with pemigatinib cessation, as seen in this case. Conclusion: As the use of FGFR 1-3 inhibitors becomes more prevalent, we aim to raise attention to the potential side effects of tumoral calcinosis.

Genomic landscape of myelodysplastic/myeloproliferative neoplasm can predict response to hypomethylating agent therapy.

There are currently no known predictors of myelodysplastic syndrome (MDS)/myeloproliferative overlap neoplasm (MPN) patients' response to hypomethylating agents (HMA). Forty-three patients with MDS/MPN who were treated with HMA during chronic phase and had next-generation sequencing using the established 63-genes panel were identified. Complete and partial remission and marrow response were assessed based on the MDS/MPN International Working Group response criteria. On univariate analysis, younger age, higher number of mutations, and mutations in SETBP1, RUNX1, or EZH2 were associated with no response. Multivariable analysis for modeling response were conducted via least absolute shrinkage and selection operator logistic regression approach, and showed that mutations in SETBP1, RUNX1, or EZH2 predict lack of HMA response. While limited by sample size, our findings suggest that genomic landscape can potentially identify MDS/MPN patients with lower likelihood of response to HMA.

Outcome of relapsed or refractory acute B-lymphoblastic leukemia patients and BCR-ABL-positive blast cell crisis of B-lymphoid lineage with extramedullary disease receiving inotuzumab ozogamicin.

Acute lymphoblastic leukemia (ALL) can relapse in the extramedullary compartment, with or without medullary involvement. Response to treatment may be individual. We evaluated response to inotuzumab ozogamicin in 31 patients with relapsed/refractory B-ALL with extramedullary disease. Median age was 31 years (range, 19-81). All patients were heavily pretreated, including allogeneic hematopoietic stem cell transplantation (HSCT; n=18). Overall response rate after two cycles of inotuzumab ozogamicin was 84% (complete remission, 55%; partial remission, 29%; resistant disease, 13%; early death, 3%). The median follow-up was 29 months and median overall survival was 12.8 months. One-year and 2-year overall survival rates were 53% (95% CI: 37-76%) and 18% (95% CI: 8-43%), respectively. Age had no impact on overall survival when assessed as a continuous variable or dichotomized at 60 years. Twelve patients proceeded to allogeneic HSCT (complete remission, n=6; partial remission, n=3; resistant disease, n=3). Prior to allogeneic HSCT, eight patients received two or fewer cycles and four patients received three or four cycles of inotuzumab ozogamicin. Sinusoidal obstruction syndrome was reported in three patients, including one after transplantation. Allogeneic HSCT, evaluated as a time-dependent variable, had no impact on overall survival. Inotuzumab ozogamicin seems to be effective as a debulking strategy in relapsed/refractory ALL with extramedullary disease. However, inotuzumab ozogamicin followed by allogeneic HSCT seems not to be effective in maintaining long-term disease control.

Post-Transplantation Cyclophosphamide-Based Graft- versus-Host Disease Prophylaxis with Nonmyeloablative Conditioning for Blood or Marrow Transplantation for Myelofibrosis.

We describe outcomes after post-transplantation cyclophosphamide and nonmyeloablative conditioning-based allogeneic blood or marrow transplantation for myelofibrosis using matched or mismatched related or unrelated donors. The conditioning regimen consisted of fludarabine, cyclophosphamide, and total body irradiation. Forty-two patients were included, with a median age of 63 years, of whom 19% had Dynamic International Prognostic Scoring System (DIPSS)-plus intermediate-1 risk, 60% had intermediate-2 risk, and 21% had high-risk disease, and 60% had at least 1 high-risk somatic mutation. More than 90% of patients engrafted neutrophils, at a median of 19.5 days, and 7% experienced graft failure. At 1 year and 3 years, respectively, overall survival was 65% and 60%, relapse-free survival was 65% and 31%, relapse was 5% and 40%, and nonrelapse mortality was 30% and 30%. Acute graft-versus-host disease grade 3-4 was seen in 17% of patients at 1 year, and chronic graft-versus-host disease requiring systemic therapy in occurred in 12% patients. Spleen size ≥17 cm or prior splenectomy was associated with inferior relapse-free survival (hazard ratio [HR], 3.50; 95% confidence interval [CI], 1.18 to 10.37; P = .02) and higher relapse rate (subdistribution HR [SDHR] not calculable; P = .01). Age >60 years (SDHR, 0.26; 95% CI, 0.08 to 0.80, P = .02) and receipt of peripheral blood grafts (SDHR, 0.34; 95% CI, 0.11 to 0.99; P = .05) were associated with a lower risk of relapse. In our limited sample, the presence of a high-risk mutation was not statistically significantly associated with an inferior outcome, although ASXL1 was suggestive of inferior survival (SDHR, 2.36; 95% CI, 0.85 to 6.6; P = .09). Overall, this approach shows outcomes comparable those of to previously reported approaches and underscores the importance of spleen size in the evaluation of transplantation candidates.

Nonmyeloablative Allogeneic Transplantation With Post-Transplant Cyclophosphamide for Acute Myeloid Leukemia With IDH Mutations: A Single Center Experience.

INTRODUCTION: Mutations in the IDH1 or IDH2 genes are detected in approximately 20% of cases of acute myeloid leukemia (AML). Few studies have examined the impact of IDH mutations in AML on allogeneic bone marrow transplant (alloBMT) outcomes. PATIENTS AND METHODS: In this single center study, alloBMT outcomes for 61 patients with IDH-mutated (mIDH) AML were compared to those for 146 patients with IDH-wildtype (wtIDH) AML. RESULTS: Patients with mIDH AML had a 2-year overall survival (OS) of 85% (95% CI 76%-95%), 2-year relapse free survival (RFS) of 71% (95% CI 59%-85%), 1-year cumulative incidence of relapse (CIR) of 14% (95% CI 5%-23%) and a 1-year cumulative incidence of transplant related mortality (CITRM) of 3% (95% CI 0%-8%). Patients with wtIDH had a 2-year OS of 61% (95% CI 53%-70%), 2-year RFS of 58% (95% CI 50%-67%), 1-year CIR of 27% (95% CI 20%-35%), and a 1-year CITRM of 9% (95% CI 5%-14%). In a univariate analysis cox-proportional hazard model, mIDH was associated with significantly better OS (HR 0.52, 95% CI 0.29-0.96) and a trend toward better RFS (HR 0.60, 95% CI 0.35-1.01). After controlling for donor age, diagnosis, and ELN risk category, mIDH was associated with a nonsignificantly improved OS (HR 0.54, 95% CI 0.29-1.01) and RFS (HR 0.67, 95% CI 0.39-1.15). CONCLUSION: Among patients with mIDH AML, patients who received a peritransplant IDH inhibitor had improved OS (P = .03) compared to those who did not, but there was no detectable difference for RFS (P = .29).

Phase II Trial of Pembrolizumab after High-Dose Cytarabine in Relapsed/Refractory Acute Myeloid Leukemia.

Immune suppression, exhaustion, and senescence are frequently seen throughout disease progression in acute myeloid leukemia (AML). We conducted a phase II study of high-dose cytarabine followed by pembrolizumab 200 mg i.v. on day 14 to examine whether PD-1 inhibition improves clinical responses in relapsed/refractory (R/R) AML. Overall responders could receive pembrolizumab maintenance up to 2 years. Among 37 patients enrolled, the overall response rate, composite complete remission (CRc) rate (primary endpoint), and median overall survival (OS) were 46%, 38%, and 11.1 months, respectively. Patients with refractory/early relapse and those receiving treatment as first salvage had encouraging outcomes (median OS, 13.2 and 11.3 months, respectively). Grade ≥3 immune-related adverse events were rare (14%) and self-limiting. Patients who achieved CRc had a higher frequency of progenitor exhausted CD8+ T cells expressing TCF-1 in the bone marrow prior to treatment. A multifaceted correlative approach of genomic, transcriptomic, and immunophenotypic profiling offers insights on molecular correlates of response and resistance to pembrolizumab. SIGNIFICANCE: Immune-checkpoint blockade with pembrolizumab was tolerable and feasible after high-dose cytarabine in R/R AML, with encouraging clinical activity, particularly in refractory AML and those receiving treatment as first salvage regimen. Further study of pembrolizumab and other immune-checkpoint blockade strategies after cytotoxic chemotherapy is warranted in AML.See related commentary by Wei et al., p. 551. This article is highlighted in the In This Issue feature, p. 549.

A randomized, phase II trial of adjuvant immunotherapy with durable TKI-free survival in patients with chronic phase CML.

PURPOSE: Chronic myeloid leukemia (CP-CML) patients can achieve undetectable minimal residual disease (UMRD) and discontinue tyrosine kinase inhibitors (TKIs). Cellular immunity plays an important role in CML disease control. We conducted a randomized, non-blinded phase II trial of adjuvant immunotherapy with TKIs to facilitate TKI discontinuation. METHODS: TKI-treated patients with CP-CML were randomized to receive the K562/GM-CSF vaccine (vaccine) OR Interferon-α + Sargramostim (IFN). If UMRD was achieved, then all treatment was stopped. Patients who did not achieve UMRD within one year, had a molecular relapse, or discontinued therapy for toxicity could crossover. RESULTS: Thirty-four patients were randomized to IFN (n = 18) or vaccine (n = 16), and 21 patients crossed over (IFN⟶vaccine: n = 9, vaccine⟶IFN, n = 12). TKIs at enrollment included imatinib (n = 31), nilotinib (n = 2), and dasatinib (n = 1). No patients discontinued vaccine due to side effects, while 33 % of IFN-treated patients discontinued treatment. More patients randomized to IFN (47.4 %, 95 % CI: 16.7-66.7 %) versus vaccine (25.0 %, 95 % CI: 0.5-43.5 %) achieved UMRD within one year. Seven patients randomized to IFN discontinued treatment with 28.6 % (95 % CI: 8.9-92.2 %) sustaining treatment-free remission (TFR) at 1 year, while three patients randomized to vaccine discontinued treatment with none sustaining TFR. Including crossover, there was a cumulative discontinuation success rate of 36.4 % (95 % CI: 16.6 %-79.5 %) after adjuvant IFN. Patients who sustained TFR received a median of 29 months of imatinib prior to discontinuation. CONCLUSION: Adjuvant IFN led to durable TFRs with limited prior TKI exposure with comparable success to prior discontinuation trials, but many patients stopped IFN early.

Mobile app validation: a digital health scorecard approach.

While digital health solutions continue to grow in number and in complexity, the ability for stakeholders in healthcare to easily discern quality lags far behind. This challenge is in part due to the lack of a transparent and standardized approach to validation. Evaluation of mobile health applications (apps) is further burdened by low barriers to development and direct-to-user marketing, leading to a crowded and confusing landscape. In this context, we investigated the pragmatic application of a previously described framework for digital health validation, the Digital Health Scorecard, in a cohort of 22 popular mobile health oncology apps. The apps evaluated using this framework performed poorly, scoring 49.4% across all evaluation criteria as a group. Performance across component domains varied considerably with cost scoring highest at 100%, usability at 56.7%, technical at 37.3%, and clinical at 15.9%. satisfaction of prospectively determined end-user requirements derived from patient, family, and clinician consensus scored 37.2%. While cost outperformed consistently and usability was adequate, the results also suggested that apps suffered from significant technical limitations, were of limited clinical value, and generally did not do what end users wanted. These large gaps further support the need for transparent and standardized evaluation to help all stakeholders in healthcare improve the quality of mobile health.

A phase II study of azacitidine in combination with granulocyte-macrophage colony-stimulating factor as maintenance treatment, after allogeneic blood or marrow transplantation in patients with poor-risk acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS).

Relapse is the most common cause of treatment failure following allogeneic blood or marrow transplantation (alloBMT) for AML or MDS. Post-transplant maintenance therapies may prevent relapse. We conducted a phase II trial combining azacitidine (AZA) with GM-CSF in non-relapsed, post-transplant patients with AML or MDS. Patients received escalating doses of AZA to a maximum of 75 mg/m2 for 5 days per cycle for up to 12 cycles. GM-CSF was given on days 1-10 of each cycle. Eighteen patients were treated following non-myeloablative (17) and myeloablative (1) alloBMT for AML (61.1%), MDS (27.7%), or therapy-related myeloid neoplasm (11.1%). The majority of patients (72%) received their graft from an HLA-haploidentical donor. The treatment was well-tolerated with rare grade 3-4 hematologic toxicities. One patient suffered an exacerbation of GVHD. The 24-month relapse-free and overall survivals were 47 and 57%, respectively, with a median of 18.6 and 29 months.

FLT3-ITD Allelic Burden and Acute Promyelocytic Leukemia Risk Stratification.

The significance of FLT3-ITD in acute promyelocytic leukemia (APL) is not well-established. We performed a bi-center retrospective study of 138 APL patients, 59 (42.8%) of whom had FLT3-ITD. APL patients with FLT3-ITD had higher baseline white blood cell counts (WBCs) (p < 0.001), higher hemoglobin, (p = 0.03), higher aspartate aminotransferase (p = 0.001), lower platelets (p = 0.004), lower fibrinogen (p = 0.003), and higher incidences of disseminated intravascular coagulation (p = 0.005), M3v variant morphology (p < 0.001), and the bcr3 isoform (p < 0.001). FLT3-ITD was associated with inferior post-consolidation complete remission (CR) (p = 0.02) and 5-year overall survival (OS) of 79.7%, compared to 94.4% for FLT3-WT (wild-type) (p = 0.02). FLT3-ITD was strongly associated with baseline WBCs ≥ 25 × 109/L (odds ratio (OR): 54.4; 95% CI: 10.4-286.1; p < 0.001). High FLT3-ITD allelic burdens correlated with high-risk (HR) Sanz scores and high WBCs, with every 1% increase in allelic burden corresponding to a 0.6 × 109/L increase in WBC. HR APL was associated with a 38.5% increase in allelic burden compared with low-risk (LR) APL (95% CI: 19.8-57.2; p < 0.001). Our results provide additional evidence that FLT3-ITD APL is a distinct subtype of APL that warrants further study to delineate potential differences in therapeutic approach.

Myeloid Neoplasm with PDGFRA Rearrangement Manifesting as a Retromolar Pad Mass.

Myeloid neoplasms with PDGFRA rearrangement are rare, and most commonly present with features of chronic eosinophilic leukemia; however, they rarely manifest as acute myeloid or lymphoblastic leukemia. Patients typically present with symptoms of hypereosinophilia including cardiovascular and pulmonary symptoms. An increase in mast cells is also a common feature of this disease, and there may be elevated serum tryptase with significant clinical overlap with systemic mastocytosis. Here, we present an unusual case of a myeloid neoplasm with PDGFRA rearrangement manifesting as a retromolar pad mass in a patient with a prior diagnosis of systemic mastocytosis. This case highlights the possibility of soft tissue involvement by myeloid neoplasms with PDGFRA rearrangement in the oral cavity. The identification of this entity is of significant clinical importance because many patients can be effectively treated with tyrosine kinase inhibitors.